--- src/gui/kernel/qclipboard_x11.cpp.sav	2014-04-25 09:52:03.855693228 +0200
+++ qt-everywhere-opensource-src-4.8.6/src/gui/kernel/qclipboard_x11.cpp	2014-04-25 09:51:58.038693777 +0200
@@ -548,7 +548,8 @@ bool QX11Data::clipboardWaitForEvent(Win
                 return false;
 
             XSync(X11->display, false);
-            usleep(50000);
+            if (!XPending(X11->display))
+                usleep(5000);
 
             now.start();
 
 
